Method of and apparatus for separating, washing, and grading lump materials



H. A. HOLZER April 9, 1940.

METHOD OF AND APPARATUS FOR SEPARATING, WASHING, AND GRADING LUMP MATERIAL 3 Sheets-Sheet 1 Filed Oct. 19, 1938 I I l l I INVENTOR ATTORNEY I I N H. A. HOLZER 2,196.451

METHOD OF AND APPARATUS FOR SEPARATING, WASHING,- AND GRADING LUMP MATERIAL I 3 Sheets-Sheet 2 Filed Oct. 10, 1938 km MM INVENTOR ATTOF'QNEY April 9, 1940.

METHOD OF AND APPARATUS FOR SEPARATING, WASHING H.IA. HOLZER 2,196,451

, AND. GRADING LUMP MATERIAL v Filed Oct. 10, 1938 3 Sheets-Sheet 3 ATTORNEY ratus.

Patented Apr. 9, 1940 UNITED STATES 'METHOD OF vAND API 'ABATUS FOR SEPA-. RATING, WASHING, AND GRADING LUMP Hiram A. Holler. Pittsbnrg. m, assigna- United Iron Works Company. Pittsbllrg, Rana, a corporationof Delaware Application ombu- 10, ms. Serial No. 234.191

0 Claims. ((120- 17) v This invention relates to a method of and apparatus for separating, grading and treating solid materials such as coal, and has for its principal object to provide a simple and eiiicient method and apparatus involving the flotation of the materials to be separated in a liquid medium having a specific gravity intermediate the specific gravities of the materials being separated.

Other objectsof the invention are to provide 9 a method and apparatus of this character wherein every particle of material is subjected to the flotation medium; to provide a method and apparatus resulting in less degradation incidental to processing; and to provide a method wherein u the processing results in ultimate uniform products which may-have dustless properties depending upon the nature of the flotation medium.

In accomplishing these and other objects of the invention, as hereinafter described, 'I" have pro-' ,v vided improved details of the structure, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. l is a. vertical longitudinal section through a coal treating apparatus embodying the features of the present invention.- I

Fig. 2 is a plan view of the apparatus.

Fig.3 is a section through the heavy material or slag removing conveyors taken on the line l-4ofF'ig.2. t

30 Fig. 4 is an enlarged crow-sectional view on the line 4-4 of Fig. l. I

midi. 5 is a cross-section on the line H of mm is an end elevational view of the appa- Fig. 7 is a fragmentary section through a modified form of apparatus.

Referring more in detail to the drawings:

" i designates an apparatus embodying the fea- 40 tures of the present invention and which includes an elongated tank having side and end walls 1-3- and 4I, the lower portionsof the side walls being shaped-to provide a plurality of legs 6 reinforced on their inner faces by upright members I varying in length toward the respective ends of the tank to connectingly mount bottom supporting members I.

. carried in the bay formed between the secon and third pair of legs nearest the endwall 4 is a transversely extending trough or hopperv I, having upwardly diverging sides It and ii .re-

spectively connected with.upwardly' inclined bo'ttom sections l2 and i3 which are supported on the members 8 to formthe bottomof the tank.

The tankis liquid-tight and of suiiicient heilht to give the desired time for separation of the materials, and is of suitable length to accommodate a feed unit l4 carried above the inclined bottom section if; and a desired number of drawof! units II, the number of which depends upon the number of grades into which the material is divided. The feed unit includes a chute II having the sides ll' tapering outwardly toward the bottom so that the chute increases in crosssection from the top toward the bottom. The upper end of the chute has a hopper i8 through which the material to be acted upon is delivered from a suitable elevator It. The lower end'of the chute extends downwardly within the tank below the level of liquid carried therein and has an inclined bottom for directing the material into a reciprocating feeder fl. 7

.In the illustrated instance the feeder includes a distributing platform 2| carried by wheels 22 I that operate on rails 23- carried on the inclined bottom II. The platform is of suflicient length to extend imder'the'inclined bottom portion of the chute and to overlap the upper edge I. of the trough I as clearly shownin Fig. 1. The front wall of the chute. terminates short of the feeder platform to provide passage for the strata of material carried on the feeder.

in the tank by pairs of'arms 24-2! is an apertured apron or screen It, the upper ends of the pairs of arms being carried by, cross shafts 21 having their ends provided with flanged wheels 28 operable on the tracks 29 formed on the rim of the tank. The respective pairs of arms are of different length to support the apron at an incline and in substantially parallel relation with the inclined bottom section II, that is, the

apron slopes upwardly from the end of the tank having the chute so that the material floats upwardly thereunder toward the opposite end. The

apron extends completely across the width of the tank, I provide guard wings 32 and I3 fixed to the inner walls of. the tank below the flanges and extending upwardly and inwardly as at 34 to terminate in flanges 35 and 36 overlapping the depending side flanges "and ii of the apron. With'this arrangement it is obvious that the material floating upwardly within the flotation medium is deflected by theguard wings and moved along the under side ofthe' apron as later described. The apron is of a length to extend from a point spaced from the chute I8 'to the end wall 5, the spacing allowing for ample reciprocatory movement of the apron when the wheels are moved on their respective tracks.

Hinged along the upper edge of the outlet opening of the chute is a deflector 31 having a free edge 38 engaging under the forward edge 38 of the apron as shown in Fig. 1. Beginning pref-' erably in spaced relation with the forward end of the apron are groups of apertures 48 with the apertures in the respective groups increasing in size toward the upper end of the aron; the respective groups of openings-registering with collectors H for receivingthe respective sized mate rials passing through the aperturesto the respective off-take conveyors 42 whereby the ultimate products are moved from the machine.

In order to reciprocate the apron, the shafts carrying the wheels 21 are connected by pitmans 43 with eccentrics 44, the eccentrics being mounted on a transverse shaft 45 having its ends journalled in suitable hearings on the side walls of the tank. The shaft 45 is driven by a pulley 46 fixed thereonand operable by a belt 41 from a prime mover such as a motor 48, as best shown in Fig. 1. The feeder 28 is operatively connected with the apron through arms 48 so that the feeder is actuated simultaneously therewith.

The collectors extend across the width tank and have upwardly sloping sides 58 terminating in spaced vertical wall portions 5| and 52 forming the side walls of the conveyor housings. The conveyors 42 are best illustrated in Fig. 5 and are shown as comprising endless belts 53 and 54 running over pairs of sprockets 55 and 58 located at. the respective sides of the tank and mounted on shafts 51 and 58 and over sprockets 58 and 58 carried on a shaft SI that is supported in sidewing extensions 62 of the-vertical wall portions 51 and 52 as shown in Fig. 5. The conveyor belts are connected by spaced blades 88 to carry the material under baffle plates 54 that extend transversely across the top of the tank at a point spaced below the normal level of liquid carried therein as shown in Fig. 5. The blades of the conveyors move the material upwardly along inclined perforated bottoms 85 that connect the wing extensions to discharge the material into chutes 55. Spaced above the bottoms 85 and at the inner sides of the lower run of the conveyors, are plates 81 forming upward eontinuations of the plates 84. The upper runs of the conveyors move over plates 88 having side edges attached to the upper edges of the wing extensions.

the liquid draining from the solid materials being moved across the apertures by the conveyor, the sump 88 having an outlet 18 by which the liquid is returned to the tank or preferably to a suitable reconcentrating apparatus (not shown), from where .the liquid, after being "reconcentrated, is returned to the tank.

85 of the respective off-takes and the opposite side wall 8 terminates in arcuate shaped extensions I4 conforming to the path of movement of the plates as they mund the sprockets 88.

Movable in'thebottoniofthetankisaoonveyorlioompi-isingendlessehainsl8and'l'l conneetedbyconveyorblades I8,

of the Formed below the bottoms 85 are sumps 88 for collecting The forward ends of the conveyor chains operate over sprockets I8 that are mounted on a shaft 88 journalled in the side walls of the tank at a point above veyor moves upwardly in the conveyor housing over a transverse partition 81 which terminates in a foraminated partition section 88 extending parallel with the bottom section I8 and terminating adjacent the sprockets 18 so that the middlings gravitating downwardly through the flotation medium are caught by the partition section 88 and carried by the. upper run of the conveyor tothe trough 88. The flne hutch material or sludge passes on through the section 88 and 'is removed by the lower run of the' conveyor and discharged into the trough 8. Theconveyor removing the middlings is driven by a sprocket 88 on the shaft 84 through a chain 88 operating over a similar sprocket 8| on a power unit 82.

Formed in the bottom of the trough 8 is a channel shaped sump 83 in which is rotatably mounted spiral conveyors 84 and 85 having flights thereon arranged to feed the material from the center of the tank toward the sides thereof for discharge through openings 88 and 81' into off-take conveyors 88 and 88. The off-take conveyors extend upwardly and rearwardly along the side walls of the tank and discharge into a receiving trough I88 by which the heavy precipitatesare discharged from the machine.

The modified form of the invention illustrated in Fig. employs a mechanical feeder in place of the chute illustrated in the preferred form, com-- prising an endless belt I8I having blades I82. The conveyor inclines downwardly into the tank in the upper portion of an inclined chute I88 and terminates in a forwardly extending discharge end I84 terminating under the reciprocatingapron' I85. The material to be treated is delivered through a hopper II! at the upper end of the conveyor housing and is discharged over a baiiie I88 to settle into the flotation liquid from pressure of the coal resting in the lower strata. This coal will then float upwardly and be caught by the blades to be carried downwardly thereby for discharge under the reciprocating apron,

' thereby assuring delivery of the coal into the tank when the mine run is not suflicient to maintain the required head in eflecting submergence to the depth necessary for direct delivery, as illustrated in the preferred form of the invention.

In using the preferred form of apparatus con- .structed and assembled as described for treating a material such ascoal, the tank is filled with a flotation medium of heavier specific gravity than the coal, for example solutions of zinc or calcium chloride. Mine run or partly prepared coal is delivered by the conveyor l8 into the hopper I8 ata rate so that a sufficient head is carried in the chute I8 to submerge the lower strata of the. coal into contact with the feeder 28 which is reciprocated incidental to its connection with the apron. The chute I8, being larger at the bottom than the top, allows free movement of the coal downwardly therein without danger of bridging or jamming of the coal. The coal, being discharged by the feeder through the outlet of the chute and of lighter specific gravity than the liquid, floats upwardly. therein to contact with the underside of the apron, The foreign material, such as rock, slag. and the like, being of heavier specific gravity than the notation liquid,

precipitates into'the "trough I. The middlings, being lighter, are carried along in the liquid and gradually precipitate and are carried by the upper run of the conveyor up the inclined partitions 88 and 81 for discharge into the trough 88, from which they are taken to a pulverizer and from there returned to the initial feed. The heavy foreign material collecting in the trough 9 is I wardly through the first group of apertures into the collector and are carried oil by the corresponding conveyor. The pieces of coal too-large to pass through the first group of perforations continue their movement under the apron and thosethat' will pass through the next group are discharged into the collector of that take-off.

The lumps of coal which are too large to pass through any of the apertures aredischarged through the opening I09 in the upper end of the apron into the last take-off. The coal delivered medium by draining thereof into the sump 69. If

desired suitable sprays I10 may be directed on the coal ash; is carried by the take-off conveyors so as to remove all of the flotation medium. The grades of coal discharged from the spout B6 are conveyed to suitable cars or storage bins.

Attention is directed to the fact that movement of the apron and the conveyors in the bottom of the tankmaintain the flotation medium in a state of agitation to prevent settling out of any of the components making up the solution. In order to assure that the tank is kept filled with the flotation medium to the point where the graded coalwill rise to' the conveyors 42, an excess amount of the medium is circulated to and from the tank inthe direction of movement of the coal, the medium being admitted by spraying it from .a nozzle ill. discharging into the upper end of the chute l8, and the excess medium I! at. the rear discharged through an overflow I end of the tank (Fig. 1).

What I claim and desire to secure by Letters Patent is: I v v 1. In an apparatus of the character described, a tank, a flotation medium in the tank for effecting movement of" materials according to their specific gravity relatively to specific gravity of said medium, .a spout having outlet into the tank below the level of said medium and above the tank bottom for maintaining a head of material to be separated in said medium, means for delivering the material to the spout, a screen extehdihg transversely of the tank in the path of rising material, means supporting the screen at an incline with respect 'to the surface of the medium in the tank so that the material is intercepted by the screen 84 d moved toward the higher end thereof while retained in submergence, said screen having groups of diflerently sized openings to pass the material according to size, means for vibrating the screen,'and means located in the tank below the outlet of said spout forremoving material falling through said medium. f

2. In an apparatus of the character described,

ties of materials to be separated, a spout extending downwardly into the tank and discharging within said flotation medium for maintaining a headoi' the material 'to be separated by said flotation medium, means for delivering the material to the spout, a feeder at the bottom of the a tank, a flotation mediumin the tank having a v specific gravity intermediate the specific gravispent for carrying the material into the flotation ing movement of materials according to their specific .gravities, means for delivering material .into the tank below the surface of the fiotation medium, a screen extending transversely of the tank and in the path. of said material, means supporting the screen at an incline with respect to the surface of the medium in the tank so that the material is moved toward the higher end thereof, said screen having groups of diiferently sized apertures topass the material according to .size, conveying means in the bottom of the tank for removing middlings, and means in the bottompf the tank for removing the heavy precipitating material;

4. In an apparatus of the character described, a tank, a flotation medium in the tank for eifect- "ing movement of materials according to their specific gravities, means for delivering lump material into the tank below the surface of the tures to pass the material according to size, and

means in the bottom of the tank for removing the heavy precipitating material, including means for separating the heavy precipitants according to size. I

5. In an apparatus of the character described.

troducing lump'materials into the lower portion of the tank in submergence in said solution, a

- a tank, a separating solution in the tank having a predetermined specific gravity, means for in-.

screen carried in the tank at a level above said J introduction point and in' submergence 'in said solution for passing selected size lumps of material. rising through the solution and into con-.

tact with the screen, means for eflecting movement of the rising material which is unable to pass through the screen to another portion oi the tank, means for separately removing the lumps passed through the screen and the lumps which are unable to pass the screen, and means located in the tank below said introduction point for removing heavy material falling through said 7 solution.

8. In an apparatus of the character described. a tank, a separating solution in the tank having a predetermined specific gravity, means for introducing lump materials into the lower portion of the tank at a point submerged within said solution, a screen located in the tank in submergence in said solution and at a level above the introduction point of the materials, said screen having openings for passing predetermined sized lumps that ascend in the solution and through the solution above the screen to float on the sur- 10 face of the solution, means for vibrating the of the tank, and means located in the tank below said introduction point for removing heavy material falling through said solution.

HIRAM A. HOLZER. 1o 

